The Organic Light Emitting Display (OLED) device possesses many outstanding properties of self-illumination, low driving voltage, high luminescence efficiency, short response time, high clarity and contrast, near 180° view angle, wide range of working temperature, applicability of flexible display and large scale full color display. The OLED is considered as the most potential display device.
The OLED can be categorized into two major types according to the driving ways, which are the Passive Matrix OLED (PMOLED) and the Active Matrix OLED (AMOLED), i.e. two types of the direct addressing and the Thin Film Transistor matrix addressing. The AMOLED comprises pixels arranged in array and belongs to active display type, which has high lighting efficiency and is generally utilized for the large scale display devices of high resolution.
The OLED display element generally comprises a substrate, an anode located on the substrate, a Hole Injection Layer located on the anode, a Hole Transporting Layer located on the Hole Injection Layer, an emitting layer located on the Hole Transporting Layer, an Electron Transport Layer located on the emitting layer, an Electron Injection Layer located on the Electron Transport Layer and a Cathode located on the Electron Injection Layer. The principle of the OLED element is that the illumination generates due to the carrier injection and recombination under the electric field driving of the semiconductor material and the organic semiconductor illuminating material. Specifically, the Indium Tin Oxide (ITO) electrode and the metal electrode are respectively employed as the anode and the cathode of the Display. Under certain voltage driving, the Electron and the Hole are respectively injected into the Electron and Hole Transporting Layers from the cathode and the anode. The Electron and the Hole respectively migrate from the Electron and Hole Transporting Layers to the Emitting layer and bump into each other in the Emitting layer to form an exciton to excite the emitting molecule. The latter can illuminate after the radiative relaxation.
The flat panel display and lighting field on the basis of OLED has been widely concerned by scientific research and academic circle in the recent years. Particularly in these few years, the flexible OLED display panel with big future has already been risen in the world, and become the competition focus of all the panel makers.
The main stream manufacture method of the flexible OLED display panel is: the glass substrate is used to be the carrier, and a layer of polyimide (PI) film is coated on the entire surface of the glass substrate, and then the PI film is cured, and the PI film serves as the flexible substrate. Then, the thin film transistor layer, the OLED element layer and the Thin Film Encapsulation layer are manufactured in order upward from the PI film. Thus, the flexible OLED display mother board is obtained. By cutting the flexible OLED display mother board, the respective flexible OLED display panels are manufactured. Because there is an entire PI film adhered on the glass substrate, it is difficult to cut with the normal knife flywheel. As using the normal knife flywheel to implement cutting, it is easy to have the issues of low cutting yield and short knife flywheel usage period. Therefore, it is required to purchase the expensive laser cutting apparatus for cutting the flexible display mother board. After cutting, the PI film and the glass substrate are separated with the Laser lift off (LLO) machine to obtain the flexible display panel. However, the price of the laser cutting apparatus in the aforesaid process is high and the energy equality needs to be strictly controlled, and then the manufacture cost is increased.